Hello I am trying to use the software to recovery files from an SD card that has been formatted and not written over. I used test disk to create an image.dd file and it was 15GB in size(SD card is 16GB?)... However when trying to run a recovery I am yielding no results. Any idea what may be the problem?

Could be that the format was not a 'quick' format. If it was a full format, then the card may have been fully wiped of data. Your dd image would still be the same size as the card, just that it is reading 0's